Asteroids

2021JD help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Amor

Perihelion (q)

1.052

Aphelion (Q)

1.559

Eccentricity (e)

0.194

Inclination (i)

3.2

deg

Orbit period (P)

545.0

Earth MOID

0.04101

U parameter

7.2

Next Earth close approach

Date

2027-04-22

Nominal distance (from Earth center)

0.17147

25651359

Maximum Brightness

25.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

26.6

mag

Diameter

13 - 29*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-05-01

Observatory

Mt. Lemmon Survey

ORBIT VISUALISATION TOOLS

External links

Proper elements

Epoch

Near present day

Near middle of observation arc

Orbit properties

Epoch
Semimajor Axis
Eccentricity (e)
Inclination (i)
Long. of Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion distance
Aphelion distance
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period
U parameter

Value

1-sigma variation

Unit

Epoch

Value

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.305700

1-sigma variation

0.000314

Unit

Eccentricity (e)

Value

0.194132

1-sigma variation

0.000161

Unit

Inclination (i)

Value

3.1900

1-sigma variation

0.0031

Unit

Long. of Ascending Node (Ω)

Value

44.1981

1-sigma variation

0.0122

Unit

Arg. of Perihelion (ω)

Value

187.3477

1-sigma variation

0.0464

Unit

Mean Anomaly (M)

Value

11.04166

1-sigma variation

0.55045

Unit

Perihelion distance

Value

1.052222

1-sigma variation

Unit

Aphelion distance

Value

1.559179

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.564806

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.043619

1-sigma variation

Unit

MOID

Value

0.041012

1-sigma variation

Unit

Orbit Period

Value

544.9589

1-sigma variation

Unit

U parameter

Value

7.2

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	9.86063E-8	5.05052E-8	9.82336E-7	-3.82561E-6	1.44145E-5	-1.72846E-4
e	5.05052E-8	2.58756E-8	5.03080E-7	-1.95957E-6	7.40043E-6	-8.85417E-5
i	9.82336E-7	5.03080E-7	9.78843E-6	-3.81116E-5	1.43458E-4	-1.72183E-3
Ω	-3.82561E-6	-1.95957E-6	-3.81116E-5	1.48425E-4	-5.59540E-4	6.70609E-3
ω	1.44145E-5	7.40043E-6	1.43458E-4	-5.59540E-4	2.14916E-3	-2.52951E-2
M	-1.72846E-4	-8.85417E-5	-1.72183E-3	6.70609E-3	-2.52951E-2	3.02999E-1

Date of computation: 2025-09-10 00:30 UTC

Note: The ASCII file is in a format suitable for Orbfit input.

Download ASCII file:

Physical properties

Rotation Period
Quality
Amplitude
Rotation Direction
Spinvector L
Spinvector B

Rotational properties

Value

Unit

Source

Rotation Period

Value

Unit

Source

[-]

Quality

Value

Unit

Source

[-]

Amplitude

Value

Unit

mag

Source

[-]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[-]

Spinvector B

Value

Unit

Source

[-]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

26.557

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

13 - 29*

Unit

Source

[2]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

Download this part as:

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

1637

Unit

Source

[1]

Normalized RMS of residuals

Value

0.776755

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-05-01.312684

Unit

Source

[2]

Last Observation

Value

2021-05-06.230789

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

31 (1)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

Unit

Source

[-]

Last Observation

Value

Unit

Source

[-]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[-]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	MPC	Minor Planet Center: https://www.minorplanetcenter.net

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Close Approaches for 2021JD from 1950 to 2125

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
MARS	1983-01-22 15:52	> 1 w	0.0480875	0.0259761	0.0250917
MARS	1990-12-14 19:53	> 1 d	0.0351953	0.0208296	0.0250467
EARTH	2015-06-08 05:27	> 1 d	0.1601823	0.1113558	0.0163013
EARTH	2018-05-24 22:44	> 1 d	0.0684413	0.0453446	0.0077737
MARS	2018-10-03 23:05	410.7	0.0440663	0.0279527	0.0066539
EARTH	2021-05-12 10:47	6.8	0.0424721	0.0423245	0.0000492
EARTH	2024-05-01 12:09	> 1 d	0.0773550	0.0524130	0.0084999
EARTH	2027-04-22 18:20	1117.6	0.1714687	0.1217957	0.0165622
EARTH	2091-06-10 03:01	> 1 d	0.1657463	0.0177705	0.0521270
EARTH	2094-05-27 06:01	> 1 w	0.0736532	0.0086931	0.0353259
EARTH	2097-05-13 12:01	> 1 d	0.0425721	0.0425073	0.0006882
MARS	2097-10-07 02:26	> 1 d	0.0241845	0.0228926	0.0058231
EARTH	2100-05-03 12:53	> 1 d	0.0783905	0.0230839	0.0394684
EARTH	2103-04-25 00:02	> 1 d	0.1715100	0.0082390	0.0560357

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
0.52581061	129.22444039	0.04273836	MINIMUM
182.48672081	311.76432607	0.57004535	SADDLE
3.34685082	312.70292212	2.04143401	SADDLE
182.23543764	131.56925312	2.56971274	MAXIMUM

Download:

MOID Plots

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